are proteins that regulate and facilitate chemical reactions at an energy level compatible with life (imagine starting a fire in your muscles to burn sugar...).
Enzymes are also emphasized on the AP because of their role in EVERY life process.
Task One: Watch the video posted below. Make notes on the important points of enzymes
Visit this website and roll through each flash animation on enzymes. Watch and understand the important points of enzymes. Task Two: Complete guided reading notes on ch 8.
Mr. V will begin the 1st half of this powerpoint, but then ask you to use the second half to complete the final task.
Task Three: Student Research Presentations posted to the wiki (Below). Research topics include:
Cofactors
Competitive Inhibitiors
Noncompetitive Inhibitors
Allosteric Activators
Allosteric Inhibitors
Feedback Inhibition
What is expected of each presentation:
a clear definition (non textbook) of each topic
a clear example of each topic
the importance of the topic relative to its function in a reaction or the human body (clinical cases or applications work well - for example disulfiram is used to treat alcoholics because it blocks the enzyme that breaks down alcohol, causing severe illness 5 minutes after having a drink).
a graphic or video clearly showing what you are explaining
Cofactors Definition: •A substance that works by changing the shape of an enzyme or assisting in the enzymatic reaction
Examples: •Vitamins serve as coenzymes which have a similar function to cofactors
•Metal Ion Activators can act as cofactors for enzymes to help normal tissue activity.
•Manganese is a specific element that is commonly used as a cofactor in the body.
Relation to the Body: •Manganese, a cofactor responsible for synthesizing fatty acids and cholesterol.
–Strengthens nerves and thought processes
–major element in body linings and connective tissues
–helps with eyesight
–enhances body’s recuperative abilities and resistance to disease.
This video sums up the majority of aspects of the enzyme. For specific information on cofactors and coenzymes, fast foward to 2:15 and a quick summary and explanation is given of each.
Kim K, Emily A, Jackie H, Martin A, Dan S Competitive Inhibitors
Noncompetitive Inhibitors
Definition: A noncompetitive inhibitor is one that binds to a site distinct from the active site; therefore they are not competing for the same site. This inhibits the substrate from binding by changing the shape of the active site of the enzyme
Example:
Diisopropyl fluorophosphate combines with the amino acid serine at the active site of the enzyme acetylcholinesterase which deactivates the neurotransmitter acetylcholine. Neurotransmitters are needed to continue the passage of nerve impulses from one neuron to another across the synapse. Acetylcholinesterase functions to deactivate the acetylcholine by breaking it down. If the enzyme is inhibited, acetylcholine accumulates and nerve impulses cannot be stopped, causing prolonged muscle contraction. Paralysis occurs and death may result since the respiratory muscles are affected.
Function: Penicillin makes disease-causing bacteria unable to form cell walls, thus making them more susceptible to the immune system. The functional group of penicillin binds to the enzyme DD-transpeptidase that links the peptidoglycan molecules in bacteria, which weakens the cell wall of the bacterium.
Graphic:
Allosteric Activators Definition:
An allosteric activator increases an enzyme's activity by binding to its specific regulatory site on the enzyme. Also known as positive allosteric control. Example:
Allosteric activation, such as the binding of oxygen molecules to hemoglobin, occurs when the binding of one ligand enhances the attraction between substrate molecules and other binding sites. With respect to hemoglobin, oxygen is effectively both the substrate and the effector. The allosteric, or "other," site is the active site protein subunit. The binding of oxygen to one subunit induces a conformational change in that subunit that interacts with the remaining active sites to enhance their oxygen affinity.
Relation to the Body:
Drugs that allosterically modulate their drug targets include the anti-anxiety drugs Valium, Xanax, Librium, and Ativan, because they increase the activity of the neurotransmitter gamma-aminobutyric acid (GABA) when it binds to its primary ligand, the benzodiazepine receptor. Amanda Plaksin
Allosteric Inhibitors Definition:
An allosteric inhibitor decreases the ability for a substrate to reach an active site by stabilizing the inactive form of the enzyme.
Example: An example of an allosteric inhibitor is strychnine, a convulsant poison, which acts as an allosteric inhibitor of glycine. Glycine is a major post-synaptic inhibitory neurotransmitter in the spinal cords and brain stems of mammals. Its binding lowers the affinity of the glycine receptor for glycine. Strychnine, thus, inhibits the action of an inhibitory transmitter, causing convulsions. Feedback Inhibition
are proteins that regulate and facilitate chemical reactions at an energy level compatible with life (imagine starting a fire in your muscles to burn sugar...).
Enzymes are also emphasized on the AP because of their role in EVERY life process.Task One: Watch the video posted below. Make notes on the important points of enzymes
Visit this website and roll through each flash animation on enzymes. Watch and understand the important points of enzymes.Task Two: Complete guided reading notes on ch 8.
Mr. V will begin the 1st half of this powerpoint, but then ask you to use the second half to complete the final task.
Task Three: Student Research Presentations posted to the wiki (Below). Research topics include:
What is expected of each presentation:
Cofactors
Definition: • A substance that works by changing the shape of an enzyme or assisting in the enzymatic reaction
Examples:
• Vitamins serve as coenzymes which have a similar function to cofactors
• Metal Ion Activators can act as cofactors for enzymes to help normal tissue activity.
• Manganese is a specific element that is commonly used as a cofactor in the body.
Relation to the Body:
• Manganese, a cofactor responsible for synthesizing fatty acids and cholesterol.
– Strengthens nerves and thought processes
– major element in body linings and connective tissues
– helps with eyesight
– enhances body’s recuperative abilities and resistance to disease.
This video sums up the majority of aspects of the enzyme. For specific information on cofactors and coenzymes, fast foward to 2:15 and a quick summary and explanation is given of each.
Kim K, Emily A, Jackie H, Martin A, Dan S
Competitive Inhibitors
Brian N.
Adam A.
Mario C.
Ilian D.
Noncompetitive Inhibitors
Definition:
A noncompetitive inhibitor is one that binds to a site distinct from the active site; therefore they are not competing for the same site. This inhibits the substrate from binding by changing the shape of the active site of the enzyme
Example:
Diisopropyl fluorophosphate combines with the amino acid serine at the active site of the enzyme acetylcholinesterase which deactivates the neurotransmitter acetylcholine. Neurotransmitters are needed to continue the passage of nerve impulses from one neuron to another across the synapse. Acetylcholinesterase functions to deactivate the acetylcholine by breaking it down. If the enzyme is inhibited, acetylcholine accumulates and nerve impulses cannot be stopped, causing prolonged muscle contraction. Paralysis occurs and death may result since the respiratory muscles are affected.
Function:
Penicillin makes disease-causing bacteria unable to form cell walls, thus making them more susceptible to the immune system. The functional group of penicillin binds to the enzyme DD-transpeptidase that links the peptidoglycan molecules in bacteria, which weakens the cell wall of the bacterium.
Graphic:
Allosteric Activators
Definition:
An allosteric activator increases an enzyme's activity by binding to its specific regulatory site on the enzyme. Also known as positive allosteric control.
Example:
Allosteric activation, such as the binding of oxygen molecules to hemoglobin, occurs when the binding of one ligand enhances the attraction between substrate molecules and other binding sites. With respect to hemoglobin, oxygen is effectively both the substrate and the effector. The allosteric, or "other," site is the active site protein subunit. The binding of oxygen to one subunit induces a conformational change in that subunit that interacts with the remaining active sites to enhance their oxygen affinity.
Relation to the Body:
Drugs that allosterically modulate their drug targets include the anti-anxiety drugs Valium, Xanax, Librium, and Ativan, because they increase the activity of the neurotransmitter gamma-aminobutyric acid (GABA) when it binds to its primary ligand, the benzodiazepine receptor.
Amanda Plaksin
Allosteric Inhibitors
Definition:
An allosteric inhibitor decreases the ability for a substrate to reach an active site by stabilizing the inactive form of the enzyme.
Example:
An example of an allosteric inhibitor is strychnine, a convulsant poison, which acts as an allosteric inhibitor of glycine. Glycine is a major post-synaptic inhibitory neurotransmitter in the spinal cords and brain stems of mammals. Its binding lowers the affinity of the glycine receptor for glycine. Strychnine, thus, inhibits the action of an inhibitory transmitter, causing convulsions.
Feedback Inhibition